issue #4880: Particle systems loading incorrectly in CocosBuilder

You must manually change the emit rate to reaching the maximum number of particles.
Bug http://www.cocos2d-x.org/issues/3990 associated emit rate.
For example. If life time for particle equal 10, emit rate 50 and total particles 1000 - amout of patricles cannot equal 1000, because emiter can spawn only 50 particles per second: 50*100 = 500 (!). 
This is not a bug, this is wrong usage.
My pull request fixed this wrong usage for particles emitter.